The Suitability of Commercially and Industrially Developed Adhesives for Polypropylene for the Conservation of Contemporary Art and Design

Polypropylene is a polyolefin, a type of plastic consisting of hydrocarbons. Polyolefins have a very low surface energy and do not easily form strong bonds with other materials. When modern artworks or design objects containing polypropylene are broken, this will cause problems during conservation treatment because adhesives used in conservation will not bond to the surface properly. Over the past decades, a common solution was to modify the surface (e.g. by chemical etching, plasma treatment), thus creating polar groups at the surface and allowing strong bonds to be formed with adhesives. Equipment for surface modification is often expensive and unavailable to conservators. Also, the irreversibility of the surface modification raises ethical questions. As a potential alternative, several recently developed commercial adhesives were tested for their suitability to bond polypropylene, keeping the conservation standards in mind. Seven adhesives were selected: two polyacrylates (3M), two epoxies (BONDiT) and three cyanoacrylates (Mesaproducts/Pattex). The adhesives were evaluated for their ageing behavior, shrinkage, workability, tensile strength (pre and post ageing) and reversibility (pre and post ageing). The adhesives proved to offer a very good solution for bonding polypropylene objects.